1. Women have a greater analgesic effect from PCA than men and consequently consume less opioids postoperatively. With longer durations of PCA (>24 hours), the difference in effect between the sexes further increases.
2. This is best explained by a difference in morphine potency with greater potency in women coupled to a slower onset and offset of the drug in women. As a consequence, morphine takes longer to induce adequate analgesia in women; a speedier effect is observed in men.
3. Because of the lower potency in men, they require multiple additional morphine administrations; women require fewer additional doses.
4. Similar to analgesia, there are gender-related differences in opioid-induced respiratory depression and nausea and vomiting, with greater effects observed in women than men.

Opioids

1. Short History
2. The Endogenous Opioid System
3. Opioid Receptor Knockout Mice
4. Classification of Exogneous Opioids
5. Opioids Acting at Opioid and Nonopioid Receptors
6. Opioid Mechanisms
7. Routes of Administration
8. Pharmcokinetics (PK) and Pharmacodynamics (PD)
9. PKPD Models for Opioid Effect: which End Point Serves the Clinician Best?
10. Pharmacodynamics: Dose Effect on Pain Relief
11. Pharmacogenetics
12. Opioid-Induced Respiratory Depression
13. Other Opioid-Related Side Effects
14. Remifentanil for Obstetric Labor Pain
15. Gender Differences